Most printers, typewriters, word processing machines and the like are arranged for typing or printing one sheet (or sets of sheets) of paper at a time. Some of these machines are provided with pin feed platens or tractors adapted to feed continuous strips or webs of paper material, but these machines are generally data processing and word processing printers of a more complicated construction. For letter quality type printers, generally a single sheet of paper is fed into the printing apparatus.
One of the disadvantages of the single sheet feed construction (either for letter size sheets or for envelopes) is that the operator must manually insert and register the sheet at the insert side of the platen and feed the sheet into the feed path thereabout. This procedure is extremely time consuming when large numbers of documents are being prepared by the printing apparatus.
Further, in many of the prior art sheet feeding devices, it is difficult to feed sequentially differently shaped or sized sheets of material. Especially difficult to feed are limp sheet material and envelopes with rolled edges which cannot be satisfactorily handled by the feeding devices of the prior art.
The term "sheet" as contemplated by the present invention is used to describe a single sheet, folded sheet such as an envelope and a unitary, multi-part form set having a plurality of interengaged sheets.
"Sheet material" as used herein refers to paper, synthetic resin, metal foil and laminates.
It is an object of the present invention to provide a novel drop sheet feeder for printing apparatus which will readily effect edge alignment of the materials being fed to increase the efficiency of printing apparatus and thereby the operator.
It is also an object to provide such a drop sheet feeder which enables the operator to provide different styles, sizes or forms of sheet materials to be fed in sequence about the platen of the printing apparatus.
Another object is to provide such a drop sheet feeder which will readily and accurately register and feed limp sheet material and envelopes with rounded edges.
A further object is to provide such a drop sheet feeder which may be fabricated readily and relatively economically and which will enjoy a long life in operation.